1. Field of the Invention
The present invention relates to lead-free solder to join an aluminum electric wire, an aluminum wire body having a connected portion joined by solder and a motor using the aluminum wire body.
2. Description of the Related Art
Until now, cooper and a cooper alloy have commonly used for conducting wires in cables used for automobiles, motors and the like. In general, these conducting wires can sufficiently conduct electricity by pressing and crimping terminals, and thus operations have been easy and connection with high electric reliability has been possible.
Cooper electric wires, however, have a heavy weight and are expensive, and thus have a problem in which the requirements of weight reduction and cost reduction which are required for automobiles, motors and the like in recent years cannot be sufficiently dealt with. Aluminum and an aluminum alloy therefore have started being examined as alternative materials for copper electric wires. When a copper electric wire is substituted for an aluminum electric wire, approximately 30 to 40% reduction as the weight reduction effect of the electric wire itself and approximately 50% reduction as material costs are expected.
There are, however, problems in that when aluminum is used for wiring, because an oxidation rate on surfaces is high, soldering processing is difficult, and when a connection method by pressing and crimping as usual is used, because a stress relaxation is likely to occur even at normal temperature after connection, the reliability of electrical connection is not obtained.
For this reason, as shown in JP 2006-179369 A, a method by inserting an aluminum electric wire into a bottom surface using a special terminal and soldering the bottom surface portion, followed by crimping is disclosed.